InterfaceDetails: Add indication of whether the OS provided tethering status

Also, check the tether status even if the system claims that 3G isn't
the active connection.
RulesActivity: Add more diagnostic information

Add active interface info, system info, preferences to Rules page.
MainActivity: Clean up calls to Log()
Create new "Log" class to capture logcat output

Add a "Logcat" section to the Rules activity, showing the last 32
events.
Switch over to the new internal Log class
RootShell: Fix watchdog timeout

If the watchdog timeout is set to 0, the application will hang forever
if the shell terminates.  The shell could terminate if a bad command
(e.g. "exit") is present in the custom script, or for other reasons
beyond the application's control.
Move log enable/disable logic into Api.java

Also, cover cases like: user asked to view the logs while logging is
disabled, or user asked to enable/disable logs while firewall is
disabled.
Api: Add afwall-{3g,wifi}-postcustom chains

These prevent the main afwall-{3g,wifi} chains from being purged on
connectivity change, allowing custom rules to safely alter them again.
strings: Spelling/grammar tweaks
Api: Make kernel and tethering strings translatable
Api: Add "special UID" entries for DNS proxy and NTP
RulesActivity: First attempt at "send error report" option
Merge pull request #188 from cernekee/debug-1.2.6.1

Debug 1.2.6.1 build